I have the 1998 version of this standard, and part (b) of this clause has the formula reversed; that is, it gives the reverse conditions to those given by Jeff Jenkins below as being those that need to be true before you can decide upon the decisive voltage, Um. Does anybody know whom I should notify of this error?
Arjen > -----Original Message----- > From: JENKINS, JEFF [mailto:[email protected]] > Sent: Tuesday, April 20, 1999 9:39 AM > To: 'Arjen Dragt'; EMC-PSTC Listserv > Subject: RE: EN 50178 clause 5.2.13 > > > Start from the lowest limit in Table 1 and work up. > > >From your example #1: > > 30/60 <= 1; > 35/(1.17*60) <= 1; > both conditions true, therefore Um < 60. > > >From your example #2: > > 200/120 <= 1; > NOT true, therefore go to next limit in Table 1; > > 200/2000 <= 1; > 205/(1.17*2000) <= 1; > both conditions true, therefore Um < 2000 > > Regards, > > Jeff Jenkins > Senior Regulatory Compliance Engineer > Advanced Energy Industries, Inc. > Fort Collins, CO USA 80525 > > Opinions are my own and not necessarily shared by Advanced Energy > Industries, Inc. or its affiliates. > > > > > -----Original Message----- > From: Arjen Dragt [mailto:[email protected]] > Sent: Monday, April 19, 1999 3:01 PM > To: EMC-PSTC Listserv > Subject: EN 50178 clause 5.2.13 > > > In case (b) of this clause, I do not understand how the decisive voltage > (classification) is to be correctly calculated. For those of you who have > the standard, try using (for example) Udc = 30 V and Udcp = 35. > The method > outlined in the standard (with the formula given) will indicate > that in this > case, Um is 2000 Vdc. > > For a voltage Udc = 200 V, Udcp = 205, the method will indicate that the > circuit lies in the Um = 120 V category. > > Either I am missing part of the "picture", or there is something > wrong with > the way that the formula is laid out. Hopefully somebody can make this > clear for me. > > > Arjen > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
